Dial arrangement for broadcast receivers



April Z8, i936. G. I EIFER ET AL 2,038,796

DIAL ARRANGEMENT FOR BROADCAST RECEIVERS Filed May 7, 1934 INVENTOR' 505721/ f/FEP BY 07,70 WEL-'55k ATTORNEY Patented Apr. 2s, 1936 L Y 2,038,796

DIAL ARRANGEMENT FOR BROADCAST RECEIVERS Gustav Leifer, Berlin-Dahlem,'and Otto Weeber,

Berlin-Charlottenburg, Germany, assignors to Telefunken Gesellschaftyfr Drahtlose kTelegraphie m. b. I-I., Berlin,-Germany, a corporation of Germany Application May "1,v 1934; serial No. 724,306' A InvGermany May 22 1933 3 claims. (ci. 11eizanv Modern broadcast receiver apparatus must while row d includes the` long wave band. A have a wave range extending at least from 200 to sheet metal plate e isimounted posteriorly of the 2,00() meters. This is not attainable by simple dial aina shiftable manner. The plate emay be tuning means so that the scheme has been adoptcaused to move from right to left, and vice versa,

5 ed to divide the above wave band into a properly by the aid of a cord or cable t which is connected so-called broadcast wave range and a longwave with the tuning knob. The same plate c has two range. The changeover of the otherwise xed slots f, g, which arealso arrangedat an angle of inductance coils is effected by what is known as a 45 degrees. wave change switch. The dial is also divi-ded into Posteri-orly of the said plate e, is another plate two parts in accordance with the said two ranges h on which the pointers or indicators are marked 10 of wave length. As a matter of fact, two dials are in the form of lines a: and y. The plate h is capausually provided, one dial bearing the station ble of longitudinal displacement in reference to the names falling inside the broadcast wave band, plate e by means of the pin p aiiixed to the plate and the -other dial bearing the names of the stae working in the slot s formed in the plate h. By

tions transmitting on the long waves. The indithe provision of a spring mechanism i the plate 15 cator device i. e., the pointer-or pointer support, h will assume one of its two terminal positions as a rule was made to pass over both scales simulin reference to e as shown in Fig. 1. In the sectaneously, and this leads often to err-ors in readond of its terminal positions the plate h will be ing. In order to obviate this diiculty the sugshifted downwardly by mechanism to be hereingestion has been made in the prior art to illumiafter `described to a position such that the upper 20 nate the dial by colored light such that on changedge of the slot s is brought to bear on the pin p. ing from one wave band to the other the color of Now, the above mentioned indicator lines n: and y the light was changed, with the result that only are so disposed that in one position only one, and those station names became visible which had the in the other position only the other one, becomes corresponding color. But an arrangement of this visible through convenient slots of the plate e. 25 kind is extremely complicated, while it involves 'Ihe shifting of the plate h in reference to the this .further drawback that the clearness of readplate e is effected simultaneously with the actuing is impaired because of the reduced brightness ation of the wave change means. The plate h of colored light. for this purpose is provided with three tongues According to this invention the above menor blades angularly bent away therefrom as indi- 30 tioned drawbacks are obviated by the aid of an cated at 1c. Behind this arrangement, and along arrangement in which in a given case only the the dial, is an angularly bent sheetlwhich is pivparticular pointer becomes visible which covers -oted at the bend or the apex of the angle and is the wave range that has been set. laterally supported at the ends of the dial. One

This is insured by disposing in front of the limb of the member l is positioned between the pointer itself a cover or closure plate which has angularly bent or oiset tongues lc of the said plate apertures roughly of the form of the pointer and h while the other one is pressed against a disk which is adapted to be shifted in front of the or cam member m by means of spring pressure. pointer in such a fashion that only one pointer The said disk is seated upon the spindle n of the will be visible depending upon the position of the wave switch and is capable of being rotated con- 40 wave switch. jointly therewith. One face o of the disk m is The drawing shows one constructional solunon-planar, in fact, it is so formed that upon rotion of the invention by way of example, with such tation of the spindle of the Wave change switch, parts as are immaterial to explain the invention one leg of the sheet metal strip l, in opposition being omitted. Fig. 1 shows a View from the rear to the force of the spring, comes to be pressed to- 45 upon the dial support, while Fig. 2 is a section wards the left hand side. As a result the other through the device. leg at the same time is pressed downwardly, and

In the iigures a is the dial support which is arin this manner the plate his entrained. A transranged upon the face or panel of the broadcast mission mechanism constructed as hereinbefore receiver set though slightly inclined rearwardly. described is necessary in order that the pointer 50 It comprises a glass slab upon which the station support may be capable of being changed at each names are inscribed in several rows, as indicated place of the scale in the same manner. by Fig. 1. To facilitate the reading, the station By an analogous application of this form of names are arranged at an angle of 45 degrees. construction and principle to an arrangement in The rows b, c, contain the broadcast wave band, which the pointer is stationary, while the dial 55 Cil tuning the apparatus through a plurality of frequency ranges, comprising a stationary Scale member having several groups of station indications marked thereon corresponding to the number of frequency ranges, said station groups be- Y ing vertically arranged, and an indicator device longitudinally movable under control of the tuning mechanism and vertically movable under control of the frequency-change switch.

2. A station indicato-r device according to claim 7, wherein said device comprises a pair of superposed plates, one of which is provided with reference marks equal in number to the frequency ranges and the other of which is provided With corresponding slots, the position of the frequencychange switch determining which one of the frequency marks is to be viewablethrough its associated slot.

3. A station indicator device for radio apparatus provided with tuning mechanism capable in there are apertures carried by said aperturedY member and movable in a vertical direction with respect thereto under the control of the frequency-change switch, the arrangement being such that in any particular position of the frequency-change switch the means vertically-movable with respect to the apertured member as'- sumes such position that only one of its indicators is viewable through an aperture and adjustment of the tuning mechanism operates to posi- 20 tion Aone of the station indications of the group corresponding to the setting of the frequencychange switch in alignment with the in-dicator viewable through the aperture. y

GUSTAV LEIFER. OTTO WEEBER. 

